Lens Drive Coil Overlap Layout for Slim Smartphone Cameras

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Solution Overview

Problem

Existing camera devices require a larger size in the optical axis direction to accommodate magnets and coils for auto-focus and shake correction functions, leading to protrusion beyond the smartphone body.

Innovation Solution

A lens driving device with a configuration of overlapping coils and magnets in perpendicular directions, combined with moving parts and guide balls, allows for autofocus and shake correction functions while minimizing the device's size in the optical axis direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If magnets and coils are disposed to perform auto focus and shake correction functions, then the camera device can achieve autofocus and handshake correction capabilities, but the device size in the optical axis direction increases causing protrusion beyond the smartphone body

Engineering Contradiction:
Improveautofocus and shake correction functionsVSAvoiddevice size in optical axis direction
Core Design Contradiction:
Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The patent applies dimensionality change by overlapping the first coil and second coil in the first direction (perpendicular to optical axis), and overlapping the first magnet and second magnet in the first direction. This allows the autofocus and shake correction components to share the same spatial footprint in the optical axis direction, reducing the overall device thickness while maintaining both functions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent merges the autofocus and shake correction functions by disposing the first coil (for autofocus) and second coil (for shake correction) in an overlapping relationship in the first direction. Similarly, the first magnet and second magnet are overlapped in the first direction. This merging of spatial arrangements allows both functions to coexist within a minimized optical axis thickness.

Inventive Principle:
Principle #5Merging (Combining)

2Length of moving object

If the device size in optical axis direction is minimized to avoid protrusion, then the smartphone appearance is improved, but it becomes difficult to accommodate both magnets and coils needed for autofocus and shake correction functions

Engineering Contradiction:
Improvedevice size in optical axis directionVSAvoidautofocus and shake correction functions
Core Design Contradiction:
Length of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent resolves this contradiction by utilizing the first direction (perpendicular to optical axis) for overlapping arrangements. The first coil and second coil are disposed to overlap in the first direction, as are the first magnet and second magnet. This allows compact packaging in the optical axis direction while maintaining sufficient space for both autofocus and shake correction components through spatial reconfiguration in the perpendicular dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent employs a nested arrangement where the first coil and second coil are positioned such that they overlap in the first direction, effectively nesting their spatial requirements. Similarly, the first magnet and second magnet are nested in the first direction. This nesting allows both sets of components to occupy overlapping projection areas, minimizing the overall device thickness in the optical axis direction.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Length of moving object

If coils and magnets are overlapped in the first direction, then the device size in optical axis direction is minimized, but the structural complexity increases

Engineering Contradiction:
Improvedevice size in optical axis directionVSAvoidcoil and magnet arrangement complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The patent manages structural complexity by systematically arranging the overlapping components in the first direction (perpendicular to optical axis). The first coil and second coil are disposed to overlap in this direction, as are the first magnet and second magnet. This organized dimensional approach provides a clear spatial framework that, while requiring precise positioning, offers a systematic solution to minimizing optical axis thickness.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The camera device can perform both autofocus and shake correction functions without protruding from the smartphone, maintaining a minimized size in both horizontal and vertical directions perpendicular to the optical axis.

Implementation Method 1

a first coil and a first magnet which move the first moving part in an optical axis direction

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

a second coil and a second magnet which move the second moving part in a first direction perpendicular to the optical axis direction

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 3

a third coil and a third magnet that move the third moving part in a second direction perpendicular to the optical axis direction and the first direction

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP4632478A1Lens driving device, camera device, and optics
Publication Date: 2025.10.15 LG INNOTEK CO LTD
  • EP4632478A1 patent drawingFigure 1
  • EP4632478A1 patent drawingFigure 2~3
  • EP4632478A1 patent drawingFigure 4~5

AI summary

A first embodiment of the present invention relates to a lens driving device comprising: a fixed part; a first moving part disposed within the fixed part; a second moving part disposed between the fixed part and the first moving part; a first coil and a first magnet which move the first moving part in an optical axis direction; and a second coil and a second magnet which move the second moving part in a first direction perpendicular to the optical axis direction, wherein the first coil overlaps the second coil in the first direction.